Forced ventilation system for Onions and Potatoes Cross-cut of forced ventilation system (with air flows). One layer ventilation boxes in front of the drying wall. Example box for drying Ventilation system for boxes. Boxes in front of ventilation system. Cross sections of boxes drying/storage. Ventilation system for drying and storage in boxes. Overview drying boxes stacked on each other. Ventilation per box level individually. Fan in ventilation system with slanted wall. Inside of ventilation system.